| 摘要 |
<p>1. A method for the treatment of condensate which is produced during the gasification of solid fuels with at least one of the gasifying agents oxygen, water vapour or carbon dioxide at a pressure of 5 to 100 bar during the step-by-step cooling of the product gas of the gasification, the product gas first being passed through a washing cooler in which the product gas is sprayed with the condensate which consists largely of water, which largely washes out halogens, that the product gas is further cooled indirectly in a waste heat boiler and condensate formed thereby is combined with the condensate from the washing cooler to form a condensate mixture containing halogens and cyanides which has temperatures of 120 to 220 degrees C, that the condensate mixture undergoes pressure relief to a lower pressure, producing flash vapour and a liquid phase, and that the flash vapour which is practically free of halogens is carried away, characterised in that the predominant portion of the liquid phase produced during pressure relief is passed directly into the washing cooler and that by adjusting the quantity of this portion the quantity of the flash vapour is set to at least 70% of the water content of the product gas which is supplied to the washing cooler, that the rest of the liquid phase is supplied to a disposal device as a halogen-rich substream, that the pH value of the liquid which is circulated through the washing cooler and the flash distillation process is set to more than 8, condensate from at least one product gas cooling process following the waste heat boiler being added to the condensate which is to be fed to the washing cooler in order to adjust the pH value, and that the pH value in the condensate mixture before pressure relief is a) either set to less than 10, whereby cyanides build up in the flash vapour, b) or set to above 10 to 12, whereby cyanides build up in the liquid phase upon pressure relief.</p> |
